Projectile for ordnance.



- No. 662,798. Patented Nov. 27, |900.

' H. S. MAXIM.

PBOJECTILE F08 ORDNANCL l l'cati n l d N v. I

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ATENT HIRAM STEVENS MAXIM, OF LONDON, ENGLAND, ASSIGNOR TO THE VIOKERS, SONS & MAXIM, LIMITED,OF SAME PLACE.

PROJECTILE Fon ORDNANCE.

SPECIFICATION forming part of Letters Patent No. 662,798, dated November 27, 1900.

Application filed November 6, 1899. Serial No. 735,975. (No model.)

To aZZ whom it' may concern:

Be it known that I, HIRAM STEVENS MAXIM, Chevalier of the Legion of Honor, civil and mechanical engineer, a citizen of the United States, residing at 1S Queens Gate Place, London,England, have invented certain new and useful Improvements in and Relating to Proj ectiles for Ordnance, of which the following is a speciiication.

This invention relates to projectiles for ordnance, and has for its object to provide an improved gas-check for preventing or mitigating the erosive action on the bore of the gun, which arises -by the incandescent gases of discharge rushing between the projectile and the surface of the gun. In some of the devices patented by myself and others for the purpose of preventing this erosive action semiplastic obturating-rings have been placed on the projectile, these rings being so made that they will expand radially outward against the bore of the gun under the gaspressure exerted upon a movable or collapsible ring or disk arranged on the base of the projectile with its rim contiguous to the semiplastic ring.

` It has been found in practice that it is extremely difficult to make the semiplastic ring of the proper degree of plasticity requiredthat is to say, if it be too plastic the paraffin Wax or tallow with which thering is provided will on the ring of the gun be suddenly squeezed backward against the pressure of the gases into the space behind the projectile, or if' the quantity of `the wax or tallow used with the said ring be inadequate the ring becomes compressed into a hard condition and will not with sufficient prom ptness spread radially outward under the pressure of the gases.

Now according to my present invention and in order toY overcome the above-stated objections I so construct and arrange on the base of the projectile, in conjunction with the semiplastic ring, a movable metal ring, disk, or base-piece, which at the instant of firing forces the said plastic ring radially outward against the bore of the gun and then as the projectile moves along the bore acts as a plunger or piston to cause a quantity of wax or tallow or other suitable substance contained in a cavity in the projectile to be contin uously forced out radially behind the semiplastic ring (or to the bore of the gun) during the whole or the greater portion of the travel of the projectile along the bore.

In order that my said invention may be clearly understood and readily carried into effect, I will proceed to describe the saine more fully with reference to the accompanying drawings, in which- Figure l is a longitudinal section of the rear portion of a projectile provided with my improved gas-check and approximately in the position it occupies within the bore of the gun prior to discharge. Eig. 2 is a similar view, but showing the position of the parts just after the discharge and when the projectile has advanced a short distance along the bore. Fig. 3 is a transverse section taken on the line l 1 of Fig. l. Fig. 4 represents sectional views of the various parts of gascheck and the rear part of the projectile separated from each other, so as to more clearly illustrate their construction.

Referring more particularly to Figs. l to 4, A is the gun-barrel; B, the projectile; O, the copper driving-band; D, the semiplastic ring, and E the movable metal base-piece. The baseof the projectile is reduced to form a circumferen tial cavity or recess b, Fig. 4, and the said base has also formed therein an annular groove or pocket b, concentric with the aforesaid circumferential cavity. This annular groove communicates with the circumferential cavity by a series of transverse holes or passages b2, Fig. 3, which extend through the outer wall b3 of the annular groove. The movable metal ring or base-piece E is constructed with two concentric circular. flanges e' e2, separated by an annular groove or space c, the flange e' being preferably of greater width than the flange e?. The flange e is adapted to enter the cavity h, while the iiange e2 is adapted to enter the annular groove b. This ring E is held in place on the base of the projectile by any suitable means, which will permit of its forward movement when subjected to the pressure of the gases in the gun, but which will not permit of its unintentional detachment from the projectile. In the drawings I have shown for this purpose a flanged IOO or dished ring F, composed of copper or other suitable metal, which is connected to the base of the projectile by means of screwsff. Between the said anged or dished rino" inner circumference of the movable ring E, I prefer to place a quantity of wax or tallow or other suitable substance f, that will act as a gas-check at this point 'and so prevent the gases of discharge from reaching the annular groove b. of the said ring F is formed with a lip f2, Which engages with a shoulder e3, formed in the said ring E. Within the annular groove b' I place the wax, tallow, or other suitable substance to be forced out behind the semiplastic ring D during the passage of the projectile'along the bore.

It will be found advantageous to make the flanges e e2 of the movable ring E loosely t the recess l and the annular groove b', so that said ring will freely move forward when subjected to the gas-pressure and to provide the said circular recess and annular groove, respectively, with tightly-fitting metal packing-pieces G H, so as to prevent the entrance of the gases of discharge into the said circular recess and annular groove.

I is a band of hemp or other appropriate fibrous material which is interposed between the semiplastic ring D and the driving-band C and which may be treated with paraffin- Wax or other substance of a similar nature to rendersaid ringsemiplastic. This band may be composed of several rings arranged edge to edge, as shown in Fig. 4.

The movable ring E may be provided at its periphery with a copper band, which when said movable ring shifts under the pressure of the gases will act upon and compress the portion of the semiplastic ring which lies outside the circumference of the movable ring. In most cases, however, I prefer to construct the aforesaid packing-piece G of such a width that it will project at its outer circumference beyond the periphery of the said ring E, as represented in the drawings. It will be found advantageous to form the outer circumference of said packing-piece G, beveled, as shown, so that its strength will be reduced at such part to permit of said circumferential portion to bend rearwardly under the pressure of the semiplastic ring during the passage of the projectile along the barrel.

The annular groove containing the Wax or tallow or other substance is preferably only partially filled therewith, so that the liange e2 of the movable ring E will not act to compress said substance and force it through the radial passages b2 until after the projectile has moved some distance along the bore.

When the gun is fired, the pressure of the powder-gases acting on the aforesaid movable ring E causes the latter to advance toward the base of the projectile and its flange e to compress the semiplastic ring D, whereby the latter is forced radially outward against the surface of the bore of the gun as the pro- The outer edge or peripheryA jectile travels along. The continued advance of the movable ringE as the semiplastic ring is squeezed out permits the flange e2 tn actnipon the material Within the annular cavity b', whereby said material is caused to passages b2 into contact with the said semiplastic ring D, as shown in Fig. 2, thus assisting in forcing the said ring radially outward against the bore of the gun as the projectile travels along said bore.

I have described the annular groove or pocket b as containing wax, tallow, or other suitable substance. By other suitable substance7 is of course intended such substance asmay be pressed out of the pocket or groove b through the passage b2into the cavity b behind the semiplastic ring D therein. This may be a substance such as Wax or tallow, specifically mentioned, or it may be a substance which is harder or softer than the two substances named. In order, therefore, that a comprehensive term may be employed for the material contained in the pocket or groove b, I call such material expressible 1. The combination with a projectile having a pocket therein containing an expressible substance, of a semiplastic ring and means actuated by the pressure of the eX- plosive charge of the gun applied behind said projectile and independent of other explosive means for forcing said eXpressible substance into engagement with said ring for expanding the latter,as and for the purpose set forth.

2. The combination with aprojectile having a pocket therein containing an expressible substance, of a semiplastic ring at one end of said projectile, and a movable basepiece for forcing said expressible substance into engagement with said ring, and expanding the latter, the said base-piece being actuated directly by the explosion of the propelling charge in the gun behind the projectile and independent of other explosive means, as and for the purpose set forth.

3. The combination with a projectile having a pocket therein containing an expressiend of said projectile, and a movable basepiece, one part of which engages said ring, and another part of which fits within said pocket, whereby upon the application of pressure upon the rear side of said base-piece, said ring is spread by said base-piece and gagement therewith to further expand said ring, as and for the purpose set forth.

4. The combination with a projectile having a recess therein, of a semiplastic ring in said recess, and a movable base-piece for forcing an eXpressible substance into said recess during the passage of the projectile along the bore of the gun, the said base-piece being actuated directljT by the explosion of the propellin g charge in the gu n behind the projectile and independent of other explosive means.

said expressible substance is forced in enbe compressed and driven through the radial IOO IIO

ble substance, of a semiplastic ring at the ring, a groove containing an expressible substance and passages betweensaid groove and recess, of a movable base-piece having two concentric ianges thereon, the outer one adapted.

to enter the recess containing the semiplastic ring and the inner one to enter the groovev containing the substance to be forced intosaid recess through said passages, the quantity of the expressible substancein said groove being such that it only partially fills the same, so as to permit the said movable base-piece to advance a short distance before acting upon and forcing the substance from said groove, as and for the purpose set forth.

7. The combination with a projectile hav- 4ing Va recess therein containing a semiplastic ring, a groove containing an expressible substance and passages between said groove and recess, of a movable base-piece in `the form of a ring, having two circular flanges thereon which tlanges'are adapted toenter, respectively, the recess containing the plastic ring andthe groove containingthe substance to be forced into said recess through said passages, the flange that enters the recess con taining the semiplastic ring being of greater wid th than the other. flange, as and for the purpose set forth.

S. The combination with a projectile having a recess therein, containing a semiplastic ring, a groove containing an expressible substance and passages between said groove and recess and groove and packing-piecesadapted to tightly fit said recesses and groove, as andfor the purpose set forth.

9. In a projectile for ordnance, the combi` nation with a semi plastic rin'g,a movable basepiece having two concentric anges, and a recess and a groove' in-the projectile for receiving said tianges, the said groove containing an expressible substance and communicating with said recess of packing-pieces adapted to tightly fit the recess and the groove, the said packing-piece for the recess being of greater width than the flange of the base-ring entering said recess and weakened at its outer periphery substantially as described. lO. In a projectile for ordnance, the combination with a semiplastic ring and a movable metallic base-ring, having two circular flanges thereon adapted to respectively engage with a recess and an annular groove in the projectile, of adished ring for securing the said base-ring to the projectile and of a gas-check interposed between said dished ring and the base-ring substantially as and for the purpose specified.

ll. In a projectile for ordnance, the conibination of a semiplastic ring,of a movable basepiece having two circular flanges thereon for engaging respectively with an annular recess and an annular groove in the projectile, of a metal driving-band and of a fibrous band interposed between said semiplastic 'ring and the driving-band substantially as and for the purpose specified.

In testimony whereof I have hereunto set m'y hand, in presence of two subscribing witnesses, this 24th day of October, 1899.

HIRAM STEVENS MAXIM. Witnesses: j

' J. COLLINS,

FRED C. HARRIS. 

